• Progress in Medical Physics
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• v.13 no.3
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• pp.109-113
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• 2002

In recent years, the radiotherapy equipment has become much more sophisticated, and with the complication comes an increased set of quality assurance (QA) responsibilities. Today's computer controlled linear accelerator requiring QA of not only the radiation integrity, but also the mechanical accuracy of the linear accelerator. The existing QA sheets are adequate for acceptance testing and commissioning but those sheets are somewhat descriptive form for routine QA. establishing the QA sheets for a facility are more efficient if the sheets could estimate the long-term stability for the result of QA. We are going to develope new prototype of mechanical QA sheet to visualize and to verify long-term stability of mechanical QA for clinical linear accelerator. The items included in mechanical QA sheet were 1) gantry rotation, 2) collimator rotation, 3) couch rotation, 4) optical distance indicator (ODI), and 5) laser alignment. We compared new prototype sheet with conventional sheet for several hospitals in Korea for those items. The QA acceptance criteria in this study mainly followed published recommendations. The contents of test for mechanical QA are the following. Confirm that the digital and/or mechanical gantry angle readouts are correct. Verify that digital and/or mechanical readouts of collimator angle agree with the true angle, as determined with the protractor. Measure the light field using a graph paper and compare with the digital readouts. Confirm digital readout accuracy. Verify that the sagittal laser, the left and right lasers, and the ceiling laser intersect at the isocenter. In the design of new QA sheet, we emphasized the representation of the long-term stability of mechanical QA by using Excel program. By using the new prototype QA sheet, we simplified and visualized the mechanical QA process, and could estimate the long-term stability of mechanical error of linear accelerator.

• The KIPS Transactions:PartD
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• v.13D no.6 s.109
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• pp.839-846
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• 2006

Context-aware adaptive service for overcoming the limitations of wireless devices and maintaining adequate service levels in changing environments is becoming an important issue. However, most existing studies concentrate on an adaptation module on the client, proxy, or server. These existing studies thus suffer from the problem of having the workload concentrated on a single system when the number of users increases md, and as a result, increases the response time to a user's request. Therefore, in this paper the adaptation module is dispersed and arranged over the client, proxy, and server. The module monitors the contort of the system and creates a proposition as to the dispersed adaptation system in which the most adequate system for conducting operations. Through this method faster adaptation work will be made possible even when the numbers of users increase, and more stable system operation is made possible as the workload is divided. In order to evaluate the proposed system, a prototype is constructed and dispersed operations are tested using multimedia based learning content, simulating server overload and compared the response times and system stability with the existing server based adaptation method. The effectiveness of the system is confirmed through this results.

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.2
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• pp.108-111
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• 2015

Purpose Lately, in accordance with the increasing interest about Healthcare accreditation program and International laboratory accreditation scheme, requirements about the instrument quality management are gradually taking shape. In nuclear medicine In vitro laboratory, the most typical instruments are multi detector gamma counter and automatic dispensing system. Each laboratory continue with the quality control adequate for circumstances. The purpose of this study is to application and establish the new Calibrator[I-125]Set which is efficient at standardization of equipment quality management. Materials and Methods Deviation between detectors were measured with 12 solid samples of the Calibrator[I-125]Set. their activities differ from each other by less than 1%. Multi detector gamma counters are GAMMA-10;Shinjin medics. Inc, Goyansi, Korea(Gamma counter A), SR300;Stratec biomedical systems AG, Gewerbestr, Germany(Gamma counter B) and COBRA II; Packard Instrument Co. Inc, Meriden, USA(Gamma counter C). Evaluation of two automatic dispensing system used A, B liquid tracer of the Calibrator[I-125]Set. After dispensing and counting, calculated using the ratio of the measured value and proposed value. We used solution A for 20, 25ul and solution B for 50, 100ul. Method of data analysis and reference range was provided by kit documentation. Furthermore, we could calculate our counter efficiency indirectly. Results The CV(%) of measured values by Gamma counter A, B, C are 0.34, 0.70, 1.30. Calculated value are 1.05314, 2.10419, 4.08485. Provided reference range is less than 3. A dispensing system's calculated values are 0.986, 0.989, 1.023, 1.017 and B are 0.874, 0.725, 1.021, 0.904. Provided reference range is from 0.95 to 1.05. Also, counter's efficiency are 74.18, 72.79, 74.32% at counter A, B, C and efficiency of the one detector counter is 79.26%. Conclusion If using this Calibrator[I-125]Set after verifying whether quality assurance, is applicable to equipment quality management on behalf of the role of gold standard.

• Journal of Multimedia Information System
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• v.1 no.2
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• pp.101-110
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• 2014

The purpose of this research is to extend Ad-hoc network system lifetime with the proposed routing protocol which has considered hop lifetimes of the nodes while guaranteeing QoS in the establishment process of Ad-hoc network communication paths. Based on another power aware routing system that proposed in the advanced research [1], we are proposing an alternative power aware routing system in which nodes' hop lifetimes are compared in order to extend the lifetime of an Ad-hoc network system and delay factors have been considered for the assurance of QoS. The research of the routing protocol in this paper, which aims to maximize the system survival time considering power consumption status during the path searching in MANET and pursues the mechanism that controls hop delays for the same reason, can be applied to the study of WSN. The study concerning such phenomena is essential so that the proposed protocol has been simulated and verified with NS-2 in Linux system focusing on the lifetimes of the hops of the nodes. Commercialization of smart devices and arrival of the ubiquitous age has brought about the world where all the people and things are connected with networks. Since the proposed power aware method and the hop delay control mechanism used to find the adequate communication paths in MANET which mainly uses batteries or in WSN, they can largely contribute to the lifetime extension of the network system by reducing power consumptions when utilized for the communications attempts among soldiers during military operation, disaster areas, temporary events or exhibitions, mobile phone shadow areas, home networks, in-between vehicle communications and sense networks, etc. This paper presents the definitions and some advantages regarding the proposed outing protocol that sustain and extend the lifetime of the networks.

• Journal of Environmental Health Sciences
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• v.35 no.4
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• pp.322-333
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• 2009

In this study, a measurement method was evaluated for the determination of polycyclic aromatic hydrocarbons (PAHs) in the ambient atmosphere. PAHs were sampled by high-volume samplers, and were then analysed with a GC/MS system. Particulate PAHs were collected on $8"{\times}10"$ quartz fiber filter, while vapor phase PAHs were adsorbed on polyurethane foam (PUF). Target compounds included a total of 36 PAHs, which are known to be frequently detected in the urban atmosphere. It was not necessary to clean-up samples before samples were analyzed using GC/MS, and the overall performance of the method was tested by a variety of quality control and quality assurance schemes. It is generally known that the clean-up procedure can negatively affect the recovery of samples. Precision and accuracy was evaluated using SRM provided by US NIST, and the results were generally satisfactory and reliable. However, the GC/MS method appeared not to be adequate for 6-rings PAHs, such as coronene, due to its lower sensitivity. In addition, collection efficiencies for low molecular compounds, such as 2-rings PAHs, were poor because of the lower retention volume of the PUF adsorbent. As a result, it was concluded that the method based on high-volume sampling and GC/MS analysis can give very reliable data by simultaneous sampling of both particulate and vapor phases for 3-rings to 5-rings PAHs of environmental concern.

• Journal of Biomedical Engineering Research
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• v.44 no.3
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• pp.190-203
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• 2023

The purpose of this study is to provide basic data to ensure the safety and essential performance of a Lower Extremity robotic assisted gait training system and to provide advanced technology and technical basis to the industry handling the system. Based on IEC 60601-1:2012/AMD2:2020 (Medical Electrical Equipment - General requirements for basic safety and essential performance of medical electrical equipment), IEC 62366-1:2015/AMD1:2020 (Medical devices - Part 1: Application of usability engineering to medical devices) and EN ISO 14971:2019 (Medical devices - Application of risk management to medical devices), the requirements for ensuring the safety and essential performance of the Lower Extremity robotic assisted gait training system were derived. Through the Delphi survey method and scenario analysis, which reflects the opinions and knowledge of experts in the fields of development, testing and review of technical documents, and quality assurance of medical devices, validity and reliability were conducted and obtained results with adequate content validity ratio (CVR; 0.7≤) and excellent reliability (Cronbach's α; 0.9≤). As a result, it was confirmed that the reliability and validity of the risk management process to ensure the safety and essential performance of the Lower Extremity robotic assisted gait training system are required a model can be established to provide measures to reduce risks according to the level of risk exposure caused by usage.

• Progress in Medical Physics
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• v.17 no.4
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• pp.212-223
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• 2006

Positional accuracy of the on-board imager (OBI) isocenter with gantry rotation was presented in this paper. Three different type of automatic evaluation methods of discrepancies between therapeutic and OBI isocenter using digital image processing techniques as well as a procedure stated in the customer acceptance procedure (CAP) were applied to check OBI isocenter migration trends. Two kinds of kV x-ray image set obtained at OBI source angle of $0^{\circ},\;90^{\circ},\;180^{\circ},\;270^{\circ}$ and every $10^{\circ}$ and raw projection data for cone-beam CT reconstruction were used for each evaluation method. Efficiencies of the methods were also estimated. If a user needs to obtain an isocenter variation map with full gantry rotation, a method taking OBI image for every $10^{\circ}$ and fitting with 5th order polynomial was appropriate. However for a mere quality assurance (QA) purpose of OBI isocenter accuracy, it was adequate to use only four OBI Images taken at the OBI source angle of $0^{\circ},\;90^{\circ},\;180^{\circ}\;and\;270^{\circ}$. Maximal discrepancy was 0.44 mm which was observed between the OBI source angle of $90^{\circ}\;and\;180^{\circ}$ OBI isocenter accuracy was maintained below 0.5 mm for a year. Proposed QA program may be helpful to Implement a reasonable routine QA of the OBI isocenter accuracy without great efforts.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.4
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• pp.314-322
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• 2008

Purpose: It is widely recognized that good quality control (QC) program is essential for adequate imaging diagnosis using gamma camera. The purpose of this study is to survey the current status of QC of gamma cameras in Republic of Korea for implementing appropriate nationwide quality control guidelines and programs. Methods: A collection of data is done for personnel, equipment and appropriateness of each nuclear medicine imaging laboratory's quality control practice. This survey is done by collection of formatted questionnaire by mails, emails or interviews. We also reviewed the current recommendations concerning quality assurance by international societies. Results: This survey revealed that practice of quality control is irregular and not satisfactory. The irregularity of the QC practice seems due partly to the lack of trained personnel, equipment, budget, time and hand-on guidelines. Conclusion: The implementation of QC program may cause additional burden to the hospitals, patients and nuclear medicine laboratories. However, the benefit of a good QC program is obvious that the hospitals can provide good quality nuclear medicine imaging studies to the patients. It is important to use least cumbersome QC protocol, to educate the nuclear medicine and hospital administrative personnel concerning QC, and to establish national QC guidelines to help each individual nuclear medicine laboratory.

• Journal of Korean Academy of Nursing Administration
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• v.1 no.2
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• pp.338-348
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• 1995

We need to continuously evaluate for nursing quality and the outcome to reflect nursing, to repair and improve of nursing. The first problem for nursing quality improvement is development of evaluation tool for the quality of nursing care. We need a system for quality assurance evaluation that is, development and framework of evaluation tool for nursing care quality. The purpose of this study was attempted to develop an evaluation tool for the quality of nursing care in musculoskeletal disorder patients. The approach method of nursing quality for the development of the tool in this study was process evaluation framework. The study were devided dvelopment process and reliability, validity verification process. The subjects of development process of this tool are three nursing export groups, and the subject of reliability, validity verification process are 20 samples of two university hospital in seoul, who were within discharge 3 months after admission treatment in musculo-skeletal disorder. Data for this study was collected from March 10 to April 13, 1995. The development process of the tool were as follows : 1. Make preliminary list of the tool by focal group were constituted 12 clinical nurses. 2. Modify and add preliminary list by 4 nursing expert panel. 3. Calculate content validity of the tool by 25 nursing expert panel of judge. 4. Verify reliability and validity of the tool. 5. Finalize an evaluation tool for the quality of the nursing care in musculo-skeletal disorder. The results of this study were as follows : 1) Development an evaluation tool for the quality of nursing care in musculo-skeletal disorder. (1) The evalution tool of this study was developed 5 standards, 33 criterias and 133 indicators. (2) 5 standards were divided according to Nursing Process. from standard 1 to standard 5, involved criterias were each 6(18%), 3(9%), 3(9%), 15(46%), 6(18%). 2) Verify reliability and validity of the tool. (1) Score of adequate degree for content validity of 33 criterias and 133 indicators were every average 2.82. (2) Inter-rater reliabilities(consentaneity score) of the tool by pearson correlation coefficient between three raters were : r=.7506, r=.8934, r=.6695. and Inter-rater reliabilities by single-facet crossed design were : r=.7464. (3) The alpha coefficient relating to internal consistency was .8524 over all 30 items of 33 criterias of developed tool. (4) Score of the quality of nursing care following to generaal characteristics of this study subjects were stastically significant differences according to educational level (F=2.93, p=.029)and diagnosing classification (F=2.50, p=.042). Through this study, I'm sure that the developed tool for the quality of patient care in musculo-skeletal disorder will show the way of more improvement of the quality of nursing care and effective nursing interventions.

• Journal of Arbitration Studies
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• v.12 no.1
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• pp.55-88
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• 2002

Arbitration Act does not have express provision about voluntary agreement for the arbitration which third party, that is, the expert confirms factual bases of party's relationship of rights and duties, determines contents of the contract, and supplements or modifies contracts, and then the parties obey the expert's decision, but it is more probable that the parties can agree to this kind of arbitration agreement as long as they freely make a contract within the scope of law. However, there is a split of authority on the scope of such arbitration agreement. Some scholars argue that the parties can only agree on the extent of the expert's confirmation about factual situations of party's relationship of rights and duties or contents of the contract. On the other hand, the other scholars argue that the parties can consent not only the expert's confirmation about factual situations of party's relationship of rights and duties or contents of contract, but also the expert's supplement or modification of contents of contract. Due to the expert's decision has effect on both parties and judges who give a judgment as a matter of law, this kind of arbitration agrement can contribute to prevent litigation. Also arbitration relieves court's burden, if such arbitration agreement was done on the important disputes. Considering that the arbitration agreement can function as a dispute resolution or a dispute prevention, it is desirable that legislators make the provision about this kind of arbitration and allow the application of arbitration Act in such arbitration agreement. Most scholars agree that the voluntary agreement for the arbitration as to third party's supplement or modification of contents of the contract can be included in the concept of a substantive law. However, it has not been concluded whether the voluntary agreement for the arbitration which follows the expert's confirmation about factual situations of party's relationship of rights and duties or contents of the contract has the nature of substantive law or procedural law. The dispute about the nature of such arbitration agreement have some shortcomings in the effect of second kind of voluntary arbitration and the applicability of procedural principles. Therefore, it will be more adequate that the focus is given to the original function of this kind of arbitration agreement and the applicability of procedural principles (the neutrality of arbitrator, the assurance of hearing of the parties) rather than the dispute regarding the nature of this kind of arbitration agreement. Considering that more attention is given to the substitutive dispute resolution these days, the function of arbitration as prevention to the litigation and resolution before the litigation should be emphasized. To do this, a legal dispute about such arbitration agreement has to be resolved. More important issues in this kind of arbitration agreement are to retain of the neutral expert and to positively inform the benefits of this institution to the public.